This invention relates to air vane governors for internal combustion engines and, in one aspect, to lawn mowers powered by an internal combustion engine including an air vane governor.
Air vane governors can be used on small internal combustion engines. This type of governor includes an air vane which is located adjacent an engine blower and is connected to the engine throttle plate which is biased toward the open position by a spring. As the engine tends to speed up under little or no load, the increased force of the air blowing against the air vane moves the throttle plate against the biasing force and toward the closed position and the engine slows down. On the other hand, as the engine speed slows down because of increased load, the reduced force of the air blowing against the air vane permits the spring to move the throttle plate toward the open position and the engine speed remains relatively constant at a pre-selected level.
Means for conveniently and rapidly adjusting the carburetor to obtain a pre-selected engine speed during initial assembly is desirable. Also, the capability of varying the governed speed during operation is often desirable. For instance, for internal combustion engines used on powered lawn mowers, it may be desirable to run the engine at a higher than usual speed for a short time, such as when cutting exceptionally heavy grass.
Examples of prior art constructions for air vane governors are disclosed in the following United States patents:
______________________________________ Patentee U.S. Pat. No. Issue Date ______________________________________ Jackson 2,525,602 Oct. 10, 1950 Hall 2,815,739 Dec. 10, 1957 Rice 3,104,657 Sept. 24, 1963 Reichenbach et al 3,161,186 Dec. 15, 1960 Glover et al 3,640,253 Feb. 8,1972 Glover et al 3,650,252 Mar. 21, 1972 ______________________________________
Attention is also directed to U.S. Pat. applications Ser. No. 915,662, filed June 15, 1978 now U.S. Pat. No. 4,221,202, and Ser. No. 915,764, filed June 15, 1978, now U.S. Pat. No. 4,220,124, both assigned to the assignee of the present application.